As a winding bobbin, for a magnetic-field coil, that is utilized in the rotor of a conventional rotating electric machine, there has been known a winding bobbin in which there are provided a winding section around which a conductor wire is wound and first and second flange sections provided on the respective sides of the winding section, in which a pair of first latching section and second latching section for latching the conductor wire are provided in the first flange section and the second flange section, respectively, and in which the winding-end section of the conductor wire that has been wound in an odd number of layers around the winding section is latched on the second and first latching sections (for example, refer to Patent Document 1).
In the case of this winding bobbin, the second latching section for latching the winding-end section of a conductor wire, wound in an odd number of layers around the winding section, is provided in the second flange section; therefore, even in the case where the number of winding layers of the conductor wire is odd, the lead wire drawn from the winding-start-side conductor wire and the lead wire drawn from the winding-end-side conductor wire can be led out in a single and the same direction, while with a simple configuration, a desired outer diameter of the coil is secured without loosening the conductor wire that has been tightly wound. Thus, because in the rotor utilizing this bobbin, the lead wire drawn from the winding-start-side conductor wire and the lead wire drawn from the winding-end-side conductor wire are led out in a single and the same direction, the rotor can readily be connected with a slip ring.